I have cut 7 mm Rem Mags to less than 24" twice. The first was to 22.75" and the second to 22". There was a velocity loss of about 65 fps between 24 and 22. Both times the handling improved. Remember that Warren Page, the first promoter of the big 7's, had a 22" barrel on Old Betsy, his 7 Mashburn Super, which has been rediscovered by Dober and BobinNH (and Hagel before them).
At 22", it will at least equal the 25-26" 280 AI's. Darn Good!
Rin-back when I did my first Mashburn (15 or so ago already...zeesh where's it go) I went 23" after chatting with Hagel about it, if I directed the bullet in the proper manner things just happened to go to Croak City Wyo rather rapidly...imagine that
Dober